Program for Producer-Consumer Problem in C | CS331 System Software Lab

Aim:Implement the producer-consumer problem using semaphores.

"If you got error! please comment below."

Program for Producer-Consumer Problem in C

#include<stdio.h>
#include<semaphore.h>
#include<pthread.h>
#include<stdlib.h>
#define buffersize 10
pthread_mutex_t mutex;
pthread_t tidP[20],tidC[20];
sem_t full,empty;
int counter;
int buffer[buffersize];
void initialize()
{
        pthread_mutex_init(&mutex,NULL);
        sem_init(&full,1,0);
        sem_init(&empty,1,buffersize);
        counter=0;
}
void write(int item)
{
        buffer[counter++]=item;
}
int read()
{
        return(buffer[--counter]);
}
void * producer (void * param)
{
        int waittime,item,i;
        item=rand()%5;
        waittime=rand()%5;
        sem_wait(&empty);
        pthread_mutex_lock(&mutex);
        printf("\nProducer has produced item: %d\n",item);
        write(item);
        pthread_mutex_unlock(&mutex);
        sem_post(&full);
}
void *consumer (void * param)
{
        int waittime,item;
        waittime=rand()%5;
        sem_wait(&full);
        pthread_mutex_lock(&mutex);
        item=read();
        printf("\nConsumer has consumed item: %d\n",item);
        pthread_mutex_unlock(&mutex);
        sem_post(&empty);
}
int main()
{
        int n1,n2,i;
        initialize();
        printf("\nEnter the no of producers: ");
        scanf("%d",&n1);
        printf("\nEnter the no of consumers: ");
        scanf("%d",&n2);
        for(i=0;i<n1;i++)
                pthread_create(&tidP[i],NULL,producer,NULL);
        for(i=0;i<n2;i++)
                pthread_create(&tidC[i],NULL,consumer,NULL);
        for(i=0;i<n1;i++)
                pthread_join(tidP[i],NULL);
        for(i=0;i<n2;i++)
                pthread_join(tidC[i],NULL);
        sleep(5);
                exit(0);
                }